The present invention relates to a nozzle for dispensing a liquid and more particularly to an improved liquid dispensing nozzle which can be magnetically latched to a fillpipe. Moreover, the present invention relates to an improved liquid dispensing magnetically latchable nozzle for control of refueling vapors.
In a preferred embodiment the nozzle is used for dispensing gasoline to a vehicle fuel tank and may include or be associated with means for directing vapors issuing from the fuel tank during refueling, and at least preventing their escape to the atmosphere.
The current air pollution abatement program contemplates specifying that during the refueling process of automobile and other vehicular gas tanks that the displaced vapors which are generated as the tanks are filled are to be recovered, such as by directing them to an on-board vehicle system where they are consumed or by returning them through the nozzle or otherwise to the supply tank. In order to achieve a relatively high degree of collection of the vapors, it is necessary to provide a tight seal between the gas dispensing nozzle and the filler neck of the vehicle fuel tank. Various attempts at accomplishing this have been tried; however, current designs rely primarily and solely on mechanical means for supporting, locking and holding the nozzle to the filler neck to obtain a mechanically tight seal. Typical prior art approaches for providing the seal include spring loaded seals and rubber bellows. Other prior art locking mechanisms for the nozzle include latching ferrules, hook-expanding toggles and U.S. Pat. Nos. 3,995,669 and 3,995,670 disclose improved liquid gas dispensing nozzles including vapor recovery means. The nozzle is locked and secured in place with respect to the filler neck by means of a spring which lockingly engages the perimeter of the neck upon insertion of the nozzle therein. At the outer end of and surrounding the gas dispensing nozzle is a magnetic seal means for providing a suitable seal for the nozzle in order that the vapors are prevented from escaping to the atmosphere and directed to an on-board vehicle system for handling of the vapors or back to the gasoline source i.e., the underground tank at the service station. Another prior art attempt is disclosed in U.S. Pat. No. 3,566,928, wherein a flexible bellows is employed to collect the vapors and the gas dispensing nozzle is mechanically secured in place in a manner similar to that for the aforediscussed patents. The seal for insuring that the vapors are collected is provided by magnetic rubber which contacts the outer extremity of the filler neck. In each of the aforementioned prior art instances the nozzle is held in place by mechanical means and each of the nozzles basically comprises a typical single non-swivel-type structure. The magnet in the aforementioned cases serves only to assist in the attachment of the rubber boot to the fillpipe. In German Pat. No. 1,163,062 the electromagnetically held nozzle is not articulated, nor does it rely on indirected flux to accomplish the attach-release operation according to the present invention.
Another problem of the prior art is that since filler sizes, designs and configurations vary quite widely between the various automobile makes and models, mechanical interlocks and tight vapor seals have only been successful on a select percentage of the present car population. A reason for this is that since the mechanical interlocks require latching to the filler neck gas cap lip, many of the cars have internal filler lips, while others have external lips, screw threads or no lips at all. This lack of standardization is a main cause for low vapor recovery efficiencies of current nozzle designs when the nozzle is self-supported and the filler neck has external lips, screw threads or no lips at all. It is, therefore quite apparent that gasoline dispensing nozzles must be adaptable to all fill neck designs.